The _Mouth_ is placed in the head, but sometimes close to the breast, as in the spider tribe; sometimes terminating in a horny beak, as in Plate 32. Fig. 1. also in Plate 42. Fig. 3 and 7. In some it is furnished with strong mandibles like pincers, as in Plate 32. Fig. 6. and Plate 37. Fig. 1, 2, 3, 4, 5, 6. In others it is so covered and guarded by the palpi, particularly among the moths, that it is not to be seen. The _Palpi_ are parts placed close to the mouth, and variously shaped; as may be seen by comparing those of the Lepidopterous with those of the Coleopterous, and other tribes; consisting of a greater or less number according to the species or genus; in some being only two, in most of them four, and in some six, (Cicindela, Carabus, Linn.) The use and purpose of these parts we are ignorant of. Fig. 1. _c c_. Fig. 2. _b_. Fig. 3. _b b_. The _Eyes_ are generally immoveable, and suited differently; in some to see only in the night, in others in the day; and differ in number according to the genera and species, having in general two only, but in some five,[18] in others eight, as the spiders. Fig. 1. _b b_. Fig. 3. _d d_. The _Tongue_ (elongated maxillæ) is sometimes curled up spirally like the spring of a watch, as in butterflies and some moths, &c. in others it (including the labium) is doubled under the head, as in bees and wasps; but a great many species are destitute of this elongated part. The THORAX is principally composed of the BACK, BREAST, and in some the SCUTELLUM, in others the MESOSTERNUM and DILATED POSTERIOR COXÆ. The _Back_, dorsum or upper part, answering to the back in some animals, terminates in some species in a triangular manner, so as to represent the scutellum, as in Plate 33. Fig. 5, 6, and 8. Tab. Ann. Fig. 1. _f_. Fig. 2. _e_. The _Breast_, or sternum, is the under part of the thorax, and always furnished with legs. The _Scutellum_ is a small but hard part like a scale, frequently of a triangular shape, placed behind the dorsum of the prothorax, and joining to it. It is not developed in every genus, being chiefly perceived in the Coleopterous, Hemipterous, and transparent-winged orders. The _Mesosternum_ is united to the fore part of the breast, extending beyond the middle legs towards the fore ones; and observable only in some species of the Coleopterous order. By Linnæus and several other authors it is called sternum. {xxiv}The _Posterior Coxæ_ are only conspicuously enlarged in some particular species (dung beetles). There are two of them placed on the sides of the breast next to the abdomen, under the hinder thighs. In some they are placed remote and distinct from it, in others they lie close; being moveable in some, in others they are fixed. The use of these parts we are ignorant of.[19]